summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/psci.c
blob: 2e6024334790299a0357e7efe1ebbfed24242c56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2012 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#define pr_fmt(fmt) "psci: " fmt

#include <linux/init.h>
#include <linux/of.h>
#include <linux/reboot.h>
#include <linux/pm.h>
#include <uapi/linux/psci.h>

#include <asm/compiler.h>
#include <asm/errno.h>
#include <asm/psci.h>
#include <asm/system_misc.h>

struct psci_operations psci_ops;

static int (*invoke_psci_fn)(u32, u32, u32, u32);
typedef int (*psci_initcall_t)(const struct device_node *);

asmlinkage int __invoke_psci_fn_hvc(u32, u32, u32, u32);
asmlinkage int __invoke_psci_fn_smc(u32, u32, u32, u32);

enum psci_function {
	PSCI_FN_CPU_SUSPEND,
	PSCI_FN_CPU_ON,
	PSCI_FN_CPU_OFF,
	PSCI_FN_MIGRATE,
	PSCI_FN_AFFINITY_INFO,
	PSCI_FN_MIGRATE_INFO_TYPE,
	PSCI_FN_MAX,
};

static u32 psci_function_id[PSCI_FN_MAX];

static int psci_to_linux_errno(int errno)
{
	switch (errno) {
	case PSCI_RET_SUCCESS:
		return 0;
	case PSCI_RET_NOT_SUPPORTED:
		return -EOPNOTSUPP;
	case PSCI_RET_INVALID_PARAMS:
		return -EINVAL;
	case PSCI_RET_DENIED:
		return -EPERM;
	};

	return -EINVAL;
}

static u32 psci_power_state_pack(struct psci_power_state state)
{
	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
			& PSCI_0_2_POWER_STATE_ID_MASK) |
		((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
		 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
		((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
}

static int psci_get_version(void)
{
	int err;

	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
	return err;
}

static int psci_cpu_suspend(struct psci_power_state state,
			    unsigned long entry_point)
{
	int err;
	u32 fn, power_state;

	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
	power_state = psci_power_state_pack(state);
	err = invoke_psci_fn(fn, power_state, entry_point, 0);
	return psci_to_linux_errno(err);
}

static int psci_cpu_off(struct psci_power_state state)
{
	int err;
	u32 fn, power_state;

	fn = psci_function_id[PSCI_FN_CPU_OFF];
	power_state = psci_power_state_pack(state);
	err = invoke_psci_fn(fn, power_state, 0, 0);
	return psci_to_linux_errno(err);
}

static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_CPU_ON];
	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
	return psci_to_linux_errno(err);
}

static int psci_migrate(unsigned long cpuid)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_MIGRATE];
	err = invoke_psci_fn(fn, cpuid, 0, 0);
	return psci_to_linux_errno(err);
}

static int psci_affinity_info(unsigned long target_affinity,
		unsigned long lowest_affinity_level)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
	return err;
}

static int psci_migrate_info_type(void)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
	err = invoke_psci_fn(fn, 0, 0, 0);
	return err;
}

static int get_set_conduit_method(struct device_node *np)
{
	const char *method;

	pr_info("probing for conduit method from DT.\n");

	if (of_property_read_string(np, "method", &method)) {
		pr_warn("missing \"method\" property\n");
		return -ENXIO;
	}

	if (!strcmp("hvc", method)) {
		invoke_psci_fn = __invoke_psci_fn_hvc;
	} else if (!strcmp("smc", method)) {
		invoke_psci_fn = __invoke_psci_fn_smc;
	} else {
		pr_warn("invalid \"method\" property: %s\n", method);
		return -EINVAL;
	}
	return 0;
}

static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
{
	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
}

static void psci_sys_poweroff(void)
{
	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
}

/*
 * PSCI Function IDs for v0.2+ are well defined so use
 * standard values.
 */
static int psci_0_2_init(struct device_node *np)
{
	int err, ver;

	err = get_set_conduit_method(np);

	if (err)
		goto out_put_node;

	ver = psci_get_version();

	if (ver == PSCI_RET_NOT_SUPPORTED) {
		/* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
		pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
		err = -EOPNOTSUPP;
		goto out_put_node;
	} else {
		pr_info("PSCIv%d.%d detected in firmware.\n",
				PSCI_VERSION_MAJOR(ver),
				PSCI_VERSION_MINOR(ver));

		if (PSCI_VERSION_MAJOR(ver) == 0 &&
				PSCI_VERSION_MINOR(ver) < 2) {
			err = -EINVAL;
			pr_err("Conflicting PSCI version detected.\n");
			goto out_put_node;
		}
	}

	pr_info("Using standard PSCI v0.2 function IDs\n");
	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_CPU_SUSPEND;
	psci_ops.cpu_suspend = psci_cpu_suspend;

	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
	psci_ops.cpu_off = psci_cpu_off;

	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_CPU_ON;
	psci_ops.cpu_on = psci_cpu_on;

	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_MIGRATE;
	psci_ops.migrate = psci_migrate;

	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN_AFFINITY_INFO;
	psci_ops.affinity_info = psci_affinity_info;

	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
		PSCI_0_2_FN_MIGRATE_INFO_TYPE;
	psci_ops.migrate_info_type = psci_migrate_info_type;

	arm_pm_restart = psci_sys_reset;

	pm_power_off = psci_sys_poweroff;

out_put_node:
	of_node_put(np);
	return err;
}

/*
 * PSCI < v0.2 get PSCI Function IDs via DT.
 */
static int psci_0_1_init(struct device_node *np)
{
	u32 id;
	int err;

	err = get_set_conduit_method(np);

	if (err)
		goto out_put_node;

	pr_info("Using PSCI v0.1 Function IDs from DT\n");

	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
		psci_ops.cpu_suspend = psci_cpu_suspend;
	}

	if (!of_property_read_u32(np, "cpu_off", &id)) {
		psci_function_id[PSCI_FN_CPU_OFF] = id;
		psci_ops.cpu_off = psci_cpu_off;
	}

	if (!of_property_read_u32(np, "cpu_on", &id)) {
		psci_function_id[PSCI_FN_CPU_ON] = id;
		psci_ops.cpu_on = psci_cpu_on;
	}

	if (!of_property_read_u32(np, "migrate", &id)) {
		psci_function_id[PSCI_FN_MIGRATE] = id;
		psci_ops.migrate = psci_migrate;
	}

out_put_node:
	of_node_put(np);
	return err;
}

static const struct of_device_id const psci_of_match[] __initconst = {
	{ .compatible = "arm,psci", .data = psci_0_1_init},
	{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
	{},
};

int __init psci_init(void)
{
	struct device_node *np;
	const struct of_device_id *matched_np;
	psci_initcall_t init_fn;

	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
	if (!np)
		return -ENODEV;

	init_fn = (psci_initcall_t)matched_np->data;
	return init_fn(np);
}